Cook the fennel till tender in lightly salted water in a pot large enough to cook the pasta in.
Remove with a slotted spoon. (Reserve cooking water)
Lay out on paper towels to drain thoroughly.
Slice into thin 2-inch strips and keep hot in a warm oven or covered casserole.
Meanwhile cook the pasta.
Drain when done.
Place in a bowl with the fennel.
Add olive oil and mix well.
Pass the cheese at table.